Note- There is a bug in Firefox 56, that causes Firefox button menu to be 'transparent' in some cases. This issue is a conflict between browsers 'hardware acceleration' and 'Firefox 56 code changes'. The only workaround is to disable 'hardware acceleration' in browser settings.

Fx55-56 noteSome future Fx57/Photon changes are already available in Firefox 55-56.CTR will not connect back & forward buttons with location bar or move stop & reload buttons back into location bar.CTR features may break with any Nightly update, some already are not working properly.

NoteMozilla removed default toolbar*.png files in Fiefox 55+.In order for some CTR features to run properly toolbar*.png files from pre-Fx55 builds had to be added to CTR.This slightly increased CTRs file size.

* Note: Custom CSS option is mainly for adding tiny code snippets to override CTR settings without installing other add-ons.It is not a replacement for Stylish add-on or userchrome.css and usercontent.css files.

To the user, who still keeps posting false error reports via "Add-on Compatibility Reporter": Are you even reading changelogs?CTR does not change/affect browsers tray content in any way (is is not able to and there is no feature in CTR that even tries that).

Setup a new browser profile without add-ons to confirm your problem is browser/OS related and not caused by add-ons like CTR.

DO NOT USE the add-on "Add-on Compatibility Reporter" to report CTR issues! There are proper ways like Mozillazine, Github or email.There even is a "Help/Support" button on CTRs preferences window.

[general change(s)]- removed 'Tabs (1) > hide tabs toolbar with one tab > reduce hiding delay' switch (Fx 47+)The 'tabs toolbar > collapsed=true' method stopped working in Firefox 47+ and got replaced by the one 'reduce hiding delay' offered.Despite of its name there might still be a visible hiding delay on startup when using MacOS.